Introducing a Quotation: Comma, Colon, or Nothing

There are three canonical ways to attach a lead-in to a quotation, and the choice is a matter of both grammar and rhythm. A comma introduces a quotation after a short reporting phrase: 'She said, "I never promised anything."' A colon introduces a quotation after a complete independent clause, especially when the quotation is longer or more formal: 'The report concluded with a single sentence: "The system is not designed for the load it now carries."' No punctuation at all is used when the quotation is grammatically integrated into the sentence: 'She described the plan as "an unfunded promise".'

The rules are conventions rather than logic. Most style guides — Chicago, AP, New Hart's Rules — agree on the three basic patterns, but disagree in the margins: some allow the colon after any reporting verb, some restrict it to formal lead-ins, and British and American practice sometimes diverge over the placement of the introducing punctuation relative to the opening quotation mark.

The rhythm consequences matter. A comma is quick and conversational; a colon is a small pause that signals importance; no punctuation gives the quotation the same weight as any other constituent of the sentence and is the best choice when the writer wants the borrowed phrase to feel woven in rather than paraded.

Common mistake: using a comma before an integrated quotation ('She said the plan was, "an unfunded promise"'). The comma is ungrammatical in an integrated construction because it interrupts a phrase that should read continuously. Either drop the comma or restructure the lead-in.